Levasil Colloidal Silica is an extremely cost-efficient, easy-to-use, and environmentally sound option for gelling sulfuric acid to obtain a solid electrolyte (gel cell) in valve-regulated, lead-acid (VRLA) batteries and for reducing the acid stratification in absorbed glass mat (AGM) batteries.

Gel batteries function via oxygen recombination. However, unlike flooded lead-acid batteries, which are filled with liquid that needs replenishing, gel batteries contain a solid electrolytic matrix – a gel of silica and sulfuric acid. This gel is created when colloidal silica particles form a network of siloxane bridges between themselves, to which sulfuric acid can then bind.

Thanks to its stable liquid dispersion, manufacturing gel batteries using colloidal silica is easier than with fumed silica. Colloidal silica is easily mixed with sulfuric acid with an in-line mixer and without the need for vacuum filling of the battery. Moreover, handling is easier and the working environment is improved because the dusting commonly associated with fumed silica is eliminated.

Depending on the customer’s specific manufacturing requirements, colloidal silica dosage can be varied. By controlling dosage and temperature, gelling time and gel strength can be optimized. Additionally, colloidal silica is an excellent acid viscosity modifier for AGM batteries at low product dosage.

A selection of our Levasil GB products for gel and AGM batteries:

 

Particle Size (µm)


pH

Solids Content

Density (g/cm3)

Viscosity

Levasil GB1000

15 nm

10

30%

1.2

< 8

Levasil GB2000

15 nm

10

40%

1.3

< 19

Levasil GB3000

7 nm

10

15%

1.1

< 10

Benefits of Levasil Colloidal Silica in gel & AGM batteries

Related applications

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